Changzhou MSW Plant Project Activated Carbon System
Project Description:
Everbright Environment Energy(Changzhou) Co., Ltd was a foreign-invested enterprise, founded in September2006 and wholly-owned by China Everbright International Limited. It was an environmental protection project aiming for MSW treatment and urban environment improvement. The project adopted BOT mode. The construction and operation period was 25.5 years. The aggregate investment of this project amounted to 412.56 million yuan. The construction scale of this project was a daily waste MSW treatment capacity of 800 tons, with two 400 t/d waste incineration furnaces. The project was equipped with two 31.05 t/h heat recovery boilers (total evaporation capacity: 62.1 t/h), one set of 12MW turbo-generator (generator output: 15MW). The annual MSW treatment capacity was about 270 thousand tons. The annual on-grid power generation capacity was about 86.15 million kWh. This project was equipped with 350 m3/d leachate treatment stations. The project had advanced process and top-notch technologies. The core equipment adopted the gratefurnace technology from Belgium SEGHERS. All environmental protection indexes were superior to the national standards, parts of them were up to the EU standards.
In order to handle the problems which appeared from time to time in the existing activated carbon dosing system, Changzhou Everbright waste incineration plant was in need of one set of standby activated carbon dosingsystem. Based on the general contracting mode of EPC, our company provided thewhole system. The designed capacity of this system could meet the requirementsof both 1 and 2# incineration line, which including automatic stabilization for operation or standby and the quantitative control on feeding process. The standby system should also try to solve the problems of dust control and weighing precision in the existing system. It was required that DCS and on-site PLC could be put into operation at the same time. The dust working environment of the system, the joint with the existing equipment and the sealing performance should all be fully considered. The system was capable of continuous feeding.
Process Design:
Activated carbon adsorption is one important process for dioxins and heavy metals treatment in a flue gas purification system of the MSW Plant. With bag filters, most of the dioxins and heavy metals in the flue gas can be removed, in order to meet the EU 2000 Standards for dioxins and heavy metals emission.
Dioxins in the flue gas exists in the form of particle, aerosol or gas. Dioxins produced by MSW incineration are mainly in the form of particle, other dioxins are mainly in the form gas. Making use of the large superficial area and excellent adsorptive performance, dioxins in both solid and gas phase can be adsorbed at the same time. Along with the bag filters, most of the dioxins can be removed from the flue gas.
Activated carbon transfer system pumps the activated carbon powder to the entrance of the bag filter mainly by compressed air. The powder is sprayed into the flue through nozzles and is mixed evenly with the flue gas to adsorb dioxins and heavy metals.